Industry Expert Blogs

New AMBA 5 ACE/AXI Specification: Rationale for Atomic Transactions

The recent update of the AMBA® 5 ACE/AXI specification introduces a number of significant performance improvements which help to align the protocol to the more recent AMBA® 5 CHI (Coherent Hub Interface) specification. One of the most prominent features is introduction of atomic transactions. Before we take a close look at this new class of transactions, let’s look back in time.

Previous generations of AMBA ACE/AXI protocols have included support of exclusive accesses which relied on the semaphore-type operations. A typical exclusive access had the following steps: